Physics Professor Awarded $150,000 NSF Grant

Atomic physics can be used to study atoms in isolation, and atomic collision physics can be used to study the way in which electrons interact. A process of particular interest is what happens when two electrons are transferred to a projectile in a collision and a single photon (a quantum of light) is liberated. The inverse of this process occurs when two electrons are liberated by a single photon. These processes tell us about how electrons "talk"with one another. Western Michigan University is one of a few places in the world where this research can be attempted due to the presence of the tandem Van de Graaff accelerator. With the accelerator and expertise of physics professor, Dr. John Tanis, the National Science Foundation has awarded a $150,000 grant to WMU to create ideal scenarios for scientists to actually view this fundamental process.

Several experiments have been conducted to observe this process, but only one has been successful. In 2009, the first successful measurement of this phenomenon was conducted at WMU with Tanis and then student, Anna Simon, from Krakow, Poland who spent six months in the WMU lab. Following the successful measurement, Tanis went to Germany in 2011 to collaborate with other top researchers, but were extremely limited by time and they were not able to produce the desired results.

Tanis believes that he will be able to get clear results at WMU because the accelerator gives him the time to conduct the research and because the accelerator allows the research to take place in a gas chamber. Tanis is interested in understanding the fundamentals of the process and knows that others will be interested in seeing the results because other scientists, including astrophysicists, will be able to see the time reverse of the process which is double ionization by a single photon.

Tanis has been active in the field of atomic collision physics, investigating fundamental interactions that occur in collisions between atomic particles for more than thirty years. He probes the dynamics and associated structural aspects of collisions between few-electron projectiles and atomic or molecular targets.  This work is carried out, with several collaborators, at WMU and at other laboratories, nationally and internationally. In addition to his research being supported by the NSF, Tanis has also been supported by the U.S. Department of Energy for more than 20 years.